Aspermatogenic seminiferous tubules were obtained from adult Wistar rats treated with Busulfan at the 20th day of foetel life. The isolated tubules converted 14C testosterone (T) into androstenedione (delta4), 3,5%) 5 alpha-dihydrotestosterone (DHT), (1%) ANd 5 alpha-androstane-3 beta, 17 beta-diol at unit gravity and incubated with 14C-T. Only delta was produced (2%). Using a similar technique the same result was obtained when pure preparation of round spermatids and primary spermatocytes from ram testis were incubated with 14C-T. From these experiments, we conclude that 5 alpha-reductase activity is present only in Sertoli cells.
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Infect Disord Drug Targets
May 2015
King's College London Dental Institute, Denmark Hill, London SE5 9RW, UK.
Objectives: Investigation of osteoblastic responses to oxidative stress, induced by C-reactive protein (CRP) and IL-6 and ameliorating effects of doxycycline (Dox); using assays for 5-alpha dihydrotestosterone (DHT) as an antioxidant marker of healing. IL-6 and CRP are risk markers of periodontitis and prevalent comorbidities in periodontitis subjects.
Methods: Confluent monolayer cultures of osteoblasts were incubated with radiolabelled testosterone (14C-T) as substrate, in the presence or absence (Control) of pre-determined optimal concentrations of CRP, IL-6, Dox; alone and in combination (n=8) for 24h in MEM.
Steroids
May 2013
Formerly at King's College London Dental Institute, Periodontology, King's College Dental Hospital, Denmark Hill, London SE5 9RW, UK.
A deproteinized natural cancellous bone mineral (B) was studied in a cell culture model for its anabolic potential using two radiolabelled steroid substrates, 14C-testosterone (14C-T) and 14C-4-androstenedione (14C-4-A) independently; in the presence or absence of the anti-androgen finasteride (F) and minocycline (M). Culture medium was assayed for the biologically active metabolite 5 alpha-dihydrotestosterone (DHT) a marker of regenerative potential and wound healing. Confluent monolayer cultures of human periosteal fibroblasts were incubated in Eagle's minimum essential medium with each of the substrates 14C-T and 14C-4-A.
View Article and Find Full Text PDFJ Clin Periodontol
June 2003
Department of Periodontology, GKT, King's Dental Hospital, London, UK.
Objectives: The aim of this investigation is to study androgen metabolism in gingival fibroblasts in response to phenytoin, oestradiol and the antioestrogen tamoxifen, in order to establish the possible role of hormones in the aetiopathogenesis of phenytoin-induced gingival overgrowth.
Materials And Methods: Six cell lines of human gingival fibroblasts were established in monolayer culture in Eagle's minimum essential medium. Duplicate incubations were performed independently with radiolabelled testosterone and 4-androstenedione, respectively (14C-T/14C-4-A), with optimal concentrations of phenytoin, oestradiol and tamoxifen alone and in combination.
J Clin Periodontol
October 2002
Division of Periodontology, Guy's, King's and St Thomas' Dental Institute, King's Dental Hospital, London, UK.
Objectives: This investigation attempts to identify the role of the alkaline phosphatase inhibitor levamisole (L) and the antiandrogen finasteride (F) on 5alpha-reductase activity in gingival fibroblasts, to elucidate mechanisms for phenytoin-induced gingival overgrowth.
Material And Methods: Human gingival fibroblasts were incubated with Eagle's MEM and 14C-testosterone/14C-4-androstenedione as substrates; effective concentrations of phenytoin (Ph), levamisole (L) and finasteride (F), alone and in combinations of (Ph + F) (Ph + L) were added to the incubate. After 24 h, the medium was analysed for steroid metabolites and quantified using a radioisotope scanner.
J Periodontol
October 1999
Department of Periodontology, Guy's King's & St. Thomas' Dental Institute, King's College, London, UK.
Background: Semisynthetic tetracyclines used in the adjunctive treatment of inflammatory periodontal disease enhance collagen expression in induced periodontal lesions of rats. Polypeptide growth factors regulate key cellular events in tissue repair. The physiologically active androgen 5 alpha-dihydrotestosterone (DHT) stimulates bone and connective tissue turnover.
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